Electron emitter



Nov. 3, 1931. H. T. REEVE ELECTRON EMITTER Filed Aug. 26, 1924v Patented ev. 3, i931 TESv or NEW Yoan. N. Y., A

rmncraon m.

Application mea August se, 19M. serial m. 734,918. e

Referring now to the drawings, the various res thereof are illustrative of the steps in the process of forming a thermionically active filament according to this invention.

Fig. 1 is a sectional view of a suitable die and block for compressing the powdered maf terial.

Fig. 2 is a section on line 2-2 of Fig. 1. Fig. 3 is a section of a suitable furnace for subjecting the rod to-'heat treatment.

Fig. 4 is a side view of the swaging machine for hammering the rod into the form of wire.

Fig. 5 is a perspective view of the hammer used in the swaging machine and 3o Fi 6 is a sectional view of a die for drawing wnthe wire into the lame'ntary form.

The iirst step in the process comprises mixtogether in powdered form, the oxide of a t ermionically active metal and a reducing agent together with the high'melting point metal to be alloyed. This mixture 1s compressed by means of the die 11 and block 12 shown in Figures 1 and 2 to form a rod The rod is then subjected to heat treatment in a vacuum or a hydrogen atmosphere in a furnace 14, such as disclosed in Figure 3.'

This treatment from its oxide while active metal the reducing oxide and is slagged o leaving an alloy of and a reducing reduces the thermionically agent takes up the oxyen released from the ducing agent and nickel powder as the hi h melting metal. With suchingredients tie reaction between the barium oxide and the aluminum would be 3BaO A12= A1203 -l- 3Ba.

IThe reactionwould be similar in case oxides of other alkaline earths or rare used instead of barium oxide. Heat applied during the reaction fuses together the mckel and thermionically active metal to form an alloy. It is of course understood that 4the alloys formed may be composed of a metal of high .melting point and one or more thermionicall's active metals.

The ro of nickel and strontium or barium are then hammered into-the form of wire by means of the swaging machine v15 Fig. 4, a hammer 16 o which is shown in Fig. 5. After' being swaged into the form of wire, the alloyis drawn down into filamentary form by being passed through a succession of dies 17, such 'as shown in Fig. 6.

What is claimed is:

process of making a thermionically activecat ode for electron discharge devices which comprises combinin a metal havin a high melting point with a aline earth oxides agent, heating the same to reduce the alkahne earth oxide and oxidize the reducing agent, and working the resultant product into filament form.

2. The rocess of m :1 athermionically active cat odefor electron discharge devices whichcomprises alkaline earth oxides, aluminum and nickel pressing said mix. ture into the form of a rod, heating said mixture in a vacuum to reduce the oxides and oxidize thereducing agent, separating aluminum oxide from the remainder and working the remainder into lamentary form.

In wmuiisis ggdedeof fA gust A D 924 mynamet's ayo u .1

HOWARD T. REEVE.

the high melting metal and thermionically I active metal.

' As a ecitic example, cally ac ve metals such as barium and stronti may be xsd with alum as the reomdes of thermioniearths were JERSEY. Assioma-.a 'ro waarnaar mimmo shown in I hereunto subscribe l 

